• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표회 논문집(I)
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• pp.167-172
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• 1998

The purpose of this study is recycling of ready mixed concrete sludge as artificial aggregate by product technique of artificial aggregate in the normal temerature. For the qulity test of artificial aggregate using ready mixed concrete sludge, it is tested in the various aspect. Therefor, Quality of artificil aggregate is suitable as coarse aggregate except absoption, abrasion. For the application of aggregate in cement concrete, Coarse aggregate are replaced with artificial aggregate using ready mixed concrete sludge 100% of volume. The results of test shown that the artificial aggregate using ready mixed concrete sludge could be used replacement of coarse aggregate in cement concrete.

• Computers and Concrete
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• 제3권2_3호
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• pp.163-175
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• 2006

This research was conducted to determine effect of pumice aggregate ratio, cement dosage and slumps on freeze-thaw resistance, density, water absorption and elasticity of concrete. In the first batch, $300kg/m^3$ cement dosage were kept constant and pumice ratios were changed as 25%, 50%, 75% and 100% of replacement for normal aggregate by volume for $3{\pm}1cm$, $5{\pm}1cm$ and $7{\pm}1cm$ slumps. Other batches were prepared with $200kg/m^3$, $250kg/m^3$, $350kg/m^3$, $400kg/m^3$ and $500kg/m^3$ cement dosages and 25% pumice aggregate +75% normal aggregate at a constant slump. Test results showed that when pumice-aggregate ratio decreased the density and freeze-thaw resistance of concretes increased. With increasing of cement dosage in the mixtures, density of the concretes increased, however, freeze-thaw resistance of concretes decreased. Water absorption of the concrete decreased with increasing cement dosage but increased with the pumice ratio. Water absorption of the concrete also decreased after freeze-thaw cycles. Freeze-thaw resistance of concretes was decreased with increasing the slumps.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문발표회
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• pp.89-94
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• 2003

Recently, the study to reduce and recycle industrial waste is underway vigorously in the various fields of industry according to the conservation of environment and resources. In construction work, the disposal problem of its waste and environmental disruption have already been serious all over the world. However the recycle of waste concrete is still at an early stage, recycled aggregate from waste concrete have only used those as subsidiary road fillers. The research institute and the company make the study that it is about the properties of recycled aggregate and those structural capacity since 1990. Through the experimentation last year, we know that strength and fluidity of recycle cement are inferior to normal cement, and admixing aggregate powder deteriorates its strength. The purpose of this study is to search for appropriate heating time and to improve performance of the recycle cement while heating hardened cement which is crushed, we investigate separating aggregate from hardened cement by preheating and improvement of strength and fluidity inrecycle cement which contains admixture.

• 한국도로학회논문집
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• 제13권1호
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• pp.169-175
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• 2011

콘크리트에서 강도는 콘크리트의 물리적 특성을 평가할 수 있는 중요한 인자 중 하나이며 콘크리트에 가장 많은 부피를 차지하는 것이 골재이다. 또한 시멘트는 콘크리트 만드는 결합재로서 이 역시 강도와 매우 밀접한 관계가 있다. 이러한 골재와 시멘트의 특성이 콘크리트 압축강도와 전단파 속도의 상관관계에 미치는 영향을 파악하고자 굵은 골재 최대치수와 시멘트 종류별로 실험을 실시하였다. 시멘트는 1종 시멘트와 초속경 시멘트를 사용했고, 골재는 서로 다른 지역의 3가지 골재를 사용하였다. 골재의 입도는 굵은 골재 최대치수 19mm와 13mm의 단입도 골재를 사용하여 동일 배합시 압축강도와 전단파 속도의 상관관계를 살펴보았다. 또한 골재의 특성을 정량화 하고자 LA마모시험을 실시하였다. 그 결과 압축강도와 전단파 속도의 상관관계는 시멘트 종류에 따라 달랐으나, 골재의 종류, 입도 및 마모감량에 관계없이 일정한 상관성을 보이는 것으로 나타났다.

• Restorative Dentistry and Endodontics
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• 제35권3호
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• pp.149-151
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• 2010

Since its introduction in 1993, Mineral Trioxide Aggregate (MTA) has been shown to be superior to others in sealing, biocompatibility, and many other aspects of clinical endodontics. MTA is primarily Portland cement with bismuth oxide as a radiopacitifier. Although some studies suggested that the reasonable-priced Portland cement could be used instead of MTA, but MTAs are different from Portland cement in its composition, especially in heavy metal contents. Therefore, clinicians should be meticulous adapting the Portland cement as a MTA substitute.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.101-102
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• 2012

A policy for recycling waste concrete has been extensively studied, but it is still lacking to recycle and reuse as a cementitious powder, and the property has big different depending on the aggregate rates. In this study, the amount of cement powder according to the internal properties of the aggregate were mixed. From as a result, Concrete Powder to play inside the aggregate composition of the cement composition CaO rigs that causes loss of power and strength reduction due to rising real water cement ratio will affect large.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 추계 학술논문 발표대회
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• pp.215-216
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• 2011

This study investigates the effect of partial replacement with cement on the properties of blast furnace slag-based mortar. Recycled fine aggregate with various contents was used to activate the hydration of blast furnace slag in the mortar and compared its effect on strength development. Results showed that increasing cement and recycled fine aggregate increased the strength of mortar specimens. However, this study found that the mortar made with partial replacement of river sand with recycled fine aggregate of 20% developed a similar strength to the strength that cement with 10% can achieved.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 추계 학술논문 발표대회
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• pp.3-4
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• 2015

Environmental load reduction and sustainable development one of the study's research into the available material is discharged, remove the coarse aggregate and fine aggregate from waste concrete and utilizing the remaining cement fine powder as an alternative raw material for limestone is the main raw material of cement developing playback cement that was the purpose. Physical over existing research and chemical quality was confirmed was evaluated for durability by promoting carbonation test, research studies on the durability evaluation insignificant. As honipyul within the aggregate differential lung fine powder increases carbonation resistance performance've found that increased sharply and, S0 showed fairly similar to the OPC. Therefore, the development within the technology research to separate fine aggregate discharge fully differential and waste fine powder is determined to be the development and use of the playback durability of the cement with the carbonation levels corresponding to the OPC if made.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.267-270
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• 2003

This study is intended to investigate the engineering properties of concrete, in which cement and fine aggregate are replaced with cement kiln dust(CKD), such as the properties of fresh concrete and hardened concrete and hydration heat history, for effective using method of CKD, a by-product produced in the process of making cement. According to the results, as the replacing ratio of CKD increases, slump and air content of concrete decreases remarkably due to an increase of viscosity and filling of the pores. As the properties of setting, initial and final setting time are shortened with an increase of the replacing ratio of CKD, and as the replacement of CKD for fine aggregate increases, setting time is shortened more greatly. Compressive strength increases due to filling of the pores and reduction of air content in comparison with plain concrete. When the replacement ratio of CKD for cement is 10% and 15%, peak temperature of hydration heat lowers slightly, but it goes up in the case of replacement of CKD for fine aggregate. Also, when cement and fine aggregate is replaced with CKD by 2.5% and 7.5% respectively(1C3S) in the case of replacement of CKD for cement and fine aggregate, it is highest.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.17-18
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• 2022

Carbon dioxide emissions in the construction sector account for 38% of all industries, and environmental destruction is occurring due to indiscriminate use of natural resources. The purpose of this study is to develop by-product aggregate Non-Sintered Cement(NSC) that can replace sand used as natural aggregate and Portland cement. Therefore, Ground Granulated Blast Furnace Slag, Type C Fly Ash and Type F Fly Ash are used to replace cement, and water granulated ferro-nickel slag(FNS) is used to replace aggregate. The flow, compressive strength and flexural strength of the formulation using sand as an aggregate and the formulation replacing 100% FNS were compared. As a result of the experiment, the formulation using FNS had higher overall strength than the formulation using sand, and as the substitution rate of Type C fly ash increased, the strength was the best. Formulation using FNS is more fluid than using sand. Through this study, we show the possibility of 100% substitution of FNS and its applicability to secondary concrete products of by-product aggregate NSC.